U.S. patent number 9,705,025 [Application Number 14/072,267] was granted by the patent office on 2017-07-11 for package structure of an optical module.
This patent grant is currently assigned to LINGSEN PRECISION INDUSTRIES, LTD.. The grantee listed for this patent is Lingsen Precision Industries, Ltd.. Invention is credited to Yu-Chen Lin, Ming-Te Tu.
United States Patent |
9,705,025 |
Tu , et al. |
July 11, 2017 |
Package structure of an optical module
Abstract
This invention relates to an optical module package structure. A
substrate is defined with a light receiving region and a light
emitting region. A light receiving chip and a light emitting chip
are disposed on the light receiving region and the light emitting
region of the substrate, respectively. An electronic unit is
disposed on the substrate and electrically connected to the light
emitting chip. Two encapsulating gels are coated on each of the
chips and the electronic unit. A cover is disposed on the substrate
and has a light emitting hole and a light receiving hole, located
above the light emitting chip and the light receiving chip,
respectively. In this way, the package structure of the optical
module of the present invention integrates passive components,
functional ICs or dies into a module, and the optical module
provides the functions of current limiting or function
adjustment.
Inventors: |
Tu; Ming-Te (Taichung,
TW), Lin; Yu-Chen (Taichung, TW) |
Applicant: |
Name |
City |
State |
Country |
Type |
Lingsen Precision Industries, Ltd. |
Taichung |
N/A |
TW |
|
|
Assignee: |
LINGSEN PRECISION INDUSTRIES,
LTD. (Taichung, TW)
|
Family
ID: |
52389750 |
Appl.
No.: |
14/072,267 |
Filed: |
November 5, 2013 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20150028359 A1 |
Jan 29, 2015 |
|
Foreign Application Priority Data
|
|
|
|
|
Jul 25, 2013 [TW] |
|
|
102126694 A |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
31/0203 (20130101); H01L 31/173 (20130101); H01L
33/54 (20130101); H01L 31/167 (20130101); H01L
2224/73265 (20130101); H01L 24/73 (20130101); H01L
2224/48091 (20130101); H01L 2224/48227 (20130101); H01L
2224/32225 (20130101); H01L 2224/48091 (20130101); H01L
2924/00014 (20130101); H01L 2224/73265 (20130101); H01L
2224/32225 (20130101); H01L 2224/48227 (20130101); H01L
2924/00 (20130101); H01L 2224/73265 (20130101); H01L
2224/32225 (20130101); H01L 2224/48227 (20130101); H01L
2924/00012 (20130101) |
Current International
Class: |
H01L
31/173 (20060101); H01L 31/0203 (20140101); H01L
33/54 (20100101); H01L 27/15 (20060101); H01L
31/167 (20060101); H01L 23/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Mondt; Johannes P
Attorney, Agent or Firm: Muncy, Geissler, Olds & Lowe,
P.C.
Claims
What is claimed is:
1. A package structure of an optical module, comprising: a
substrate being defined with a light receiving region and a light
emitting region; a light receiving chip disposed on the light
receiving region of the substrate; a light emitting chip disposed
on the light emitting region of the substrate; an electronic unit
disposed on the substrate and electrically connected to the light
emitting chip; two encapsulating gels coated on the light receiving
chip, the light emitting chip and the electronic unit; and a cover
disposed on the substrate and having a light emitting hole and a
light receiving hole, and the light emitting hole and the light
receiving hole being located above the light emitting chip and the
light receiving chip, respectively, wherein the cover has a first
receiving space and a second receiving space individually separated
from the first receiving space, wherein the first receiving space
and the second receiving space are connected to the light receiving
hole and the light emitting hole, respectively, wherein the light
receiving chip and the light emitting chip are received in the
first receiving space and the second receiving space, respectively,
and the electronic unit is received in the first receiving space,
wherein one of the two encapsulating gels is filled in the light
receiving hole and the first receiving space, and the other of the
two encapsulating gels is filled in the light emitting hole and the
second receiving space.
2. The package structure of the optical module as claimed in claim
1, wherein each of the encapsulating gels and the cover are made of
light transmissive resin and opaque resin, respectively.
3. The package structure of the optical module as claimed in claim
1, wherein the substrate is a non-ceramic substrate, which
comprises an organic Bismaleimide Triazine substrate.
4. A packaging method of an optical module, the method comprising
the following steps of: (a) defining an emitting region and a
receiving region on a substrate; (b) electrically connecting an
electronic unit to the substrate; (c) electrically connecting a
light receiving chip and a light emitting chip to the receiving
region and the emitting region of the substrate, respectively; (d)
disposing an opaque cover on the substrate, wherein the cover has a
light emitting hole, a light receiving hole, a first receiving
space and a second receiving space individually separated from the
first receiving space, and the first receiving space and the second
receiving space are connected to the light receiving hole and the
light emitting hole, respectively, the light receiving chip and the
light emitting chip are received in the first receiving space and
the second receiving space, respectively, and the electronic unit
is received in the first receiving space; (e) forming two light
transmissive encapsulating gels on each of the chips and the
electronic unit; and (f) filling one of the two encapsulating gels
in the light receiving hole and the first receiving space, and
filling the other of the two encapsulating gels in the light
emitting hole and the second receiving space.
5. The packaging method of the optical module as claimed in claim
4, wherein the electronic unit and the substrate are disposed by
Surface Mount Technology.
6. The packaging method of the optical module as claimed in claim
4, wherein the electronic unit and the light emitting chip are
electrically connected in series or in parallel.
7. The packaging method of the optical module as claimed in claim
4, wherein each of the chips is electrically connected to the
substrate by a wire bonding process and a die attaching process.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a package structure, especially
related to a package structure of an optical module.
Descriptions of the Related Art
Currently, optical proximity sensing modules have become a
mainstream technology choice of the new generation of intelligent
electronic devices (such as smart phones). When the electronic
device is close to someone's ears (face detection) or placed in a
pocket, the module will immediately turn off the screen display to
save power and prevent accidental screen presses to provide a
better user experience. The action principle of the module is
emitting a light source with a light emitting chip, such as a light
emitting diode (LED), the light is reflected by the surface of an
object and is then projected onto a light receiving chip to be
converted to electrical signals for subsequent processing.
Taiwan Patent M428490 provides a package structure of an optical
module. The package structure comprises a substrate, a light
emitting chip, a light receiving chip, a cover and two
encapsulating gels. Each of the chips is disposed on a substrate.
The cover having a light emitting hole and a light receiving hole
is affixed on the substrate and covers the light emitting chip and
the light receiving chip separately to form chambers, respectively.
Each of the encapsulating gels is filled in each of the chambers to
coat each of the chips in order to achieve the above purposes.
However, the internal components of the optical module mainly
comprise the light emitting chip and the light receiving chip, and
the optical module only works after being equipped with other
functional modules or related passive components. This way leads to
an overall structure volume increase of the whole optical elements
and the high assembly costs.
In summary, the conventional optical module has the above drawbacks
and needs to be improved.
SUMMARY OF THE INVENTION
The main objective of the present invention is to provide a package
structure of an optical module to effectively reduce the volume of
the whole structure and to decrease the packaging costs.
In order to achieve the above objective, the package structure of
an optical module of the present invention comprises a substrate, a
light emitting chip, a light receiving chip, an electronic unit,
two encapsulating gels and a cover. The substrate is defined with a
light receiving region and a light emitting region. The light
receiving chip is disposed on the light receiving region of the
substrate. The light emitting chip is disposed on the light
emitting region of the substrate. The electronic unit is disposed
on the substrate and is electrically connected to the light
emitting chip. Each of the encapsulating gels is coated on the
light receiving chip, the light emitting chip and the electronic
unit. The cover is disposed on the substrate and has a light
emitting hole and a light receiving hole, and the light emitting
hole and the light receiving hole are located above the light
emitting chip and the light receiving chip, respectively.
Each of the encapsulating gels and the cover are made of light
transmissive resin and opaque resin, respectively.
The cover has a first receiving space and a second receiving space,
and the first receiving space and the second receiving space are
connected to the light emitting hole and the light receiving hole,
respectively.
The light receiving chip and the light emitting chip are received
in the first receiving space and the second receiving space,
respectively.
The substrate is a non-ceramic substrate, which comprises an
organic Bistmaleimide Triazine substrate.
The present invention further provides a packaging method of an
optical module, and the method comprises the following steps
of:
(a) defining an emitting region and a receiving region on a
substrate;
(b) electrically connecting the electronic unit to the
substrate;
(c) electrically connecting a light receiving chip and a light
emitting chip to the emitting region and the receiving region of
the substrate, respectively;
(d) disposing an opaque cover on the substrate; and
(e) forming light transmissive encapsulating gels on each of the
chips and the electronic unit.
The electronic unit and the substrate are disposed by Surface Mount
Technology.
The electronic unit and the light emitting chip are electrically
connected in series or in parallel.
Each of the chips is electrically connected to the substrate by a
wire bonding process and a die attaching process.
The packaging method further comprises a step (f) of cutting or
punching the optical module made in the step (a) to step (d).
Thereby, the package structure of the optical module of the present
invention integrates the electronic units, such as passive
elements, functional ICs and dies, into one package structure. The
optical module of the present invention having the design of
electrically connecting the electronic unit and the light emitting
chip provides the functions of current limiting or function
adjustment without being cooperated with other modules. Therefore,
compared to the conventional art, the present invention not only
decreases the work process of assembling and packaging but also
reduces the whole structure volume and decreases the packaging
costs.
To provide a further understanding of the composition,
characteristics and purpose of the present invention, the following
are descriptions describe several embodiments of the present
invention to explain the drawings in detail for people skilled in
this technical field can implement. The following description lists
the embodiments to merely illustrate the technical contents and
characteristics of the present invention. People have a general
knowledge of this technical field of the present invention can
proceed with various simple modifications, replacements, or member
omitting belonging to the scope of the present invention intended
to protect.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a preferred embodiment of the present
invention;
FIG. 2 is a cross-sectional view along the 2-2 section line of FIG.
1 of a preferred embodiment of the present invention; and
FIG. 3 is a packaging flow diagram of a preferred embodiment of the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In order to illustrate the structure, characteristics and
effectiveness of the present invention in detail, a preferred
embodiment and corresponding diagrams are illustrated as
follows.
Please refer to FIG. 1 and FIG. 2. The package structure of an
optical module 10 provided by a preferred embodiment of the present
invention is cut from a module of the package array and comprises a
substrate 20, a light receiving chip 30, a light emitting chip 40,
an electronic unit 50, two encapsulating gels 60, and a cover
70.
The substrate 20 in the preferred embodiment is a non-ceramic
substrate, such as a Bismaleimide Triazine (known as BT) substrate
or a glass fiber (known as FR4) substrate made of organic
materials. Thereby, the material cost of the substrate 20 is low.
The surface of the substrate 20 is defined with a light receiving
region 22 and a light emitting region 24.
The light emitting chip 40 and the light receiving chip 30 are
treated by a die attaching process and a wire bonding process and
are disposed on the light receiving region 22 and the light
emitting region 24 of the substrate 20. The light emitting chip 40
is used to emit light, and the light receiving chip 30 is used to
receive the light emitted from the light emitting chip 40.
The electronic unit 50 is disposed on the substrate 20 by Surface
Mount Technology and is electrically connected to the light
emitting chip 40 in series or in parallel. Thereby, the light
emitting chip 40 has a function of current limiting or function
adjustment.
Each of the encapsulating gels 60 is made of light transmissive
resin, such as transparent epoxy resin. Each of the encapsulating
gels 60 is coated on the light receiving chip 30 and the light
emitting chip 40, respectively, and each of the encapsulating gels
60 is disposed on the light emitting chip 40 and the light
receiving chip 30, respectively.
The cover 70 is integrally molded with the opaque resin, such as
opaque epoxy resin. The cover 70 is disposed on the substrate 20
and each of the encapsulating gels 60. The cover 70 has a light
receiving hole 72, a light emitting hole 74, a first receiving
space 76 connected to the light receiving hole 72 and a second
receiving space 78 connected to the light emitting hole 74. The
light receiving hole 72 and the light emitting hole 74 are located
above the light emitting chip 40 and the light receiving chip 30,
respectively, and the light receiving chip 30 and the light
emitting chip 40 are received in the first receiving space 76 and
the second receiving space 78, respectively.
FIGS. 3(A) to 3(E) show the packaging process of the optical module
of the present invention. The first step A is defining the light
receiving region 22 and the light emitting region 24 on a single
substrate 20 of each array substrate. The second step B is
disposing the electronic units 50 on the substrate 20 by surface
mount technology. The third step C is disposing the light receiving
chip 30 and the light emitting chip 40 on the light receiving
region 22 and the light emitting region 24 of the substrate 20,
respectively, by a die attaching process and a wire bonding
process. The fourth step D is positioning the opaque cover 70 at a
predetermined position, and the predetermined position in the
present embodiment is to form the light receiving hole 72 and the
light emitting hole 74 of the cover 70 above the light receiving
chip 30 and the light emitting chip 40. The cover is cap attached
on the substrate 20. The light receiving chip 30, the light
emitting chip 40 and the electronic unit 50 are received in the
first receiving space 76 and the second receiving space 78,
respectively. The fifth step E is filling the light transmissive
encapsulating gels 60 through the light receiving hole 72 and the
light emitting hole 74 of the cover 70. The encapsulating gels 60
are filled in the first receiving space 76 and the second receiving
space 78 and coat the light receiving chip 30 and the light
emitting chip 40. Thereby, the light transmission loss and
distortion happened between the light emitting chip 40 and the
light receiving chip 30 is reduced, and the chips 30, 40 are
protected.
In summary, the electronic unit 50 of the optical module of the
present invention provides electrical signals with current limiting
or function adjustment to the light emitting chip 40 for light
emission. The light emitted from the light emitting chip 40 passes
the encapsulating gels 60 and then projected on the surface of the
object through the light emitting hole 74 of the cover 70. The
light reflected from the surface of the object is received through
the light receiving hole 72 of the cover 70 and is projected on the
encapsulating gels 60. The light is then transmitted though the
encapsulating gels 60 to the light receiving chip 30. The light
receiving chip 30 converts the received light signals into
electrical signals for operation processing. In this way, the
package structure of the optical module of the present invention
integrates electronic units, such as passive components, functional
ICs or dies, into a single package structure. With the design of
electrically connecting the electronic unit and the light emitting
chip, the optical module of the present invention provides the
functions of current limiting or function adjustment without being
cooperated with other modules. Therefore, compared to the
conventional art, the present invention not only decreases the work
process of assembling and packaging but also reduces the whole
structure volume and decreases the packaging costs.
The constituent elements in the above embodiments of the present
invention are only for illustration and are not intended to limit
the scope of the present invention. Other substitutions, equivalent
elements or changes should be covered by the scope of the claim of
the present invention.
* * * * *